18-200 VR vs 18-135 Nikon lens comparison
Credit to Bill for the "focus nerdvana" post
Here is a very quick comparison from close-up distance b/w the 18-200 and the 18-135. Tripod, shutter delay, all else the same (ISO400, F/6.3, 1/400s).
This is 100% center crop, unedited from camera JPG, all normal except sharpness +1. Resized to fit Nikonians' drakonian size limitations
How to read:
First row is 18-135 at 135mm: from left to right I have taken several images with only the first one autofocused, the others I have moved the tripod back to compensate for slight backfocus. I measured the standard deviation and it coinsides with the visually sharpest third square. The sharpness increases from the first to the third peaking at the fourth, then declines after that. This confirmes my observation of slight backfocus of this seconf D80 I tested, but this is irrelevant for the lens test since both lenses appear to behave similarly in terms of focus.
Second row is the same with the 18-200 at 135 (VR off)
Third Row is the 18-200 at 200mm (VR off)
The three cells in the right most column show the standard deviation at various other focal lengths with the 18-135 on the top.
So, it seems that the 18-200 compared to the 18-135 is slightly softer at the wide angle, slightly sharper in the middle (50mm) and again slightly softer towards the tele end. The 18-200 appears to have slightly better corner to corner consistency too, but I did not test carefully for this.
Any comments or experience you may have would be appreciated.
Here is the larger unresized 100% crop:
Attachment#1 (jpg file)
#1. "RE: 18-200 VR vs 18-135 Nikon lens comparison" | In response to Reply # 0kocho Basic MemberTue 28-Nov-06 05:33 PM
Anyone else with observations?
I shot some outdoor photos with both lenses today and the test target observations so far hold true: the 18-135 is a little sharper at almost all focal lengths, except at mid-zoom (I tested at 50 and 70mm) where the 18-200 is a little sharper. However, with some contrasty scenes such as tree leaves/needles against sky the 18-200 at say 135mm behaves better due to its better control of CA. Stopping either lens to F/8 did not change much there with the 18-135 still showing quite a bit of CA. I only shot JPG so some RAW CA removal might minimize this but I can't check as I do not have the Nikon Capture NX software.
The sharpness gained wtih using VR at say 1/30s and ISO100 does not look any better to me than increasing ISO 3-4 times and shooting with the 18-135. That would of course only be true at low ISO to start and at still reasonable durations - things change above ISO800 where noise problems would be more detrimental than a little camera shake induced softness (not talking large shakes here, but what just softens the image a little). With VR at shorter focal lengths 1/2 second shots are very possible, where without VR I have to stay above 1/10 to get similar results.
The extended range from 135mm to 200mm I really do not think makes much of a difference, so I would discount that as a decision criteria b/w the two lenses.
Cost aside, if I had to choose one over the other as a general purpose lens, I would probably prefer to use the 18-200 VR due to it being more versatile with VR and its better control of CA, light fall off, and corner sharpness (though it is less than stellar on either of these two lenses IMO). I have not evaluated distortion, but the 18-200 is pretty bad so I find it hard to think the 18-135 woul be any worse.
There are certainly many scenes where the 18-135 would turn-up slightly crisper results in most of its range and if VR is not essential, being 1/2 the cost and noticeably smaller and lighter, I think it would be a very close second choice for me.